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ATI Radeon HD 4670, Redefining The Mainstream
Date: Sep 10, 2008
Author: Marco Chiappetta
Introduction and Specifications

We have explained in numerous articles in the past that the bulk of GPU sales are made in the form of ether IGPs (Integrated Graphics Processors) or affordable, mainstream graphics cards.  As powerful and exciting as the ATI Radeon HD 4870 X2 or GeForce  GTX 280 cards may be, AMD and NVIDIA simply don't sell as many flagship products as they do mainstream cards.

It is because of this fact that both companies consistently refresh their mainstream offerings every few months or so, and continually push new features and performance down their respective product lines.  As many of you may have expected, since AMD recently released the RV770 GPU, which is the foundation of the Radeon HD 4800 series, a new mainstream offering was obviously in the works.  And today, we can finally show that card to you.

AMD is releasing a new salvo of mainstream graphics cards that should fall in the sub-$80 price segment, dubbed the Radeon HD 4670.  The GPU at the heart of the 4670 is based on the RV770 architecture used on the Radeon HD 4800 series, sans a few stream processors, ROPs, and other assorted elements, but with what is essentially the same feature set as its more expensive counterparts.  We've got a couple of these new cards on hand and plan to show you what they're capable of on the pages ahead. After reading, you may be surprised by what 80 bucks can get you these days...

ATI Radeon HD 4670

AMD ATI Radeon HD 4670
Specifications and Features

514 million transistors on 55nm fabrication process

PCI Express 2.0 x16 bus interface

GDDR3/DDR3/DDR2 memory interface (depending on model)

Microsoft DirectX 10.1 support

  • Shader Model 4.1
  • 32-bit floating point texture filtering
  • Indexed cube map arrays
  • Independent blend modes per render target
  • Pixel coverage sample masking
  • Read/write multi-sample surfaces with shaders
  • Gather4 texture fetching
Unified Superscalar Shader Architecture
  • 320 stream processing units
    • Dynamic load balancing and resource allocation for vertex, geometry, and pixel shaders
    • Common instruction set and texture unit access supported for all types of shaders
    • Dedicated branch execution units and texture address processors
  • 128-bit floating point precision for all operations
  • Command processor for reduced CPU overhead
  • Shader instruction and constant caches
  • Up to 128 texture fetches per clock cycle
  • Up to 128 textures per pixel
  • Fully associative multi-level texture cache design
  • DXTC and 3Dc+ texture compression
  • High resolution texture support (up to 8192 x 8192)
  • Fully associative texture Z/stencil cache designs
  • Double-sided hierarchical Z/stencil buffer
  • Early Z test and Fast Z Clear
  • Lossless Z & stencil compression (up to 128:1)
  • Lossless color compression (up to 8:1)
  • 8 render targets (MRTs) with anti-aliasing support
  • Physics processing support
Dynamic Geometry Acceleration
  • High performance vertex cache
  • Programmable tessellation unit
  • Accelerated geometry shader path for geometry amplification
  • Memory read/write cache for superior stream output performance
Anti-aliasing features
  • Multi-sample anti-aliasing (2, 4 or 8 samples per pixel)
  • Up to 24x Custom Filter Anti-Aliasing (CFAA) for superior quality
  • Adaptive super-sampling and multi-sampling
  • Gamma correct
  • Super AA (ATI CrossFireX configurations only)
  • All anti-aliasing features compatible with HDR rendering
Texture filtering features
  • 2x/4x/8x/16x high quality adaptive anisotropic filtering modes (up to 128 taps per pixel)
  • 128-bit floating point HDR texture filtering
  • sRGB filtering (gamma/degamma)
  • Percentage Closer Filtering (PCF)
  • Depth & stencil texture (DST) format support
  • Shared exponent HDR (RGBE 9:9:9:5) texture format support
OpenGL 2.0 support

ATI CrossFireX Multi-GPU Technology
  • Scale up rendering performance and image quality with two GPUs
  • Integrated compositing engine
  • High performance bridge interconnect

ATI Avivo HD Video and Display Platform
  • 2nd generation Unified Video Decoder (UVD 2)
    • Enabling hardware decode acceleration of H.264, VC-1 and MPEG-2
    • Dual stream playback (or Picture-in-picture)
  • Hardware MPEG-1, and DivX video decode acceleration
    • Motion compensation and IDCT
  • ATI Avivo Video Post Processor
    • Enhanced DVD up-conversion to HD
    • Color space conversion
    • Chroma subsampling format conversion
    • Horizontal and vertical scaling
    • Gamma correction
    • Advanced vector adaptive per-pixel de-interlacing
    • De-blocking and noise reduction filtering
    • Detail enhancement
    • Inverse telecine (2:2 and 3:2 pull-down correction)
    • Bad edit correction
    • Automatic dynamic contrast adjustment
    • Full score in HQV (SD) and HQV (HD) video quality benchmarks
  • Two independent display controllers
    • Drive two displays simultaneously with independent resolutions, refresh rates, color controls and video overlays for each display
    • Full 30-bit display processing
    • Programmable piecewise linear gamma correction, color correction, and color space conversion
    • Spatial/temporal dithering provides 30-bit color quality on 24-bit and 18-bit displays
    • High quality pre- and post-scaling engines, with underscan support for all display outputs
    • Content-adaptive de-flicker filtering for interlaced displays
    • Fast, glitch-free mode switching
    • Hardware cursor
  • Two integrated DVI display outputs
    • Primary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI) or 2560x1600 (dual-link DVI)
    • Secondary supports 18-, 24-, and 30-bit digital displays at all resolutions up to 1920x1200 (single-link DVI only)
    • Each includes a dual-link HDCP encoder with on-chip key storage for high resolution playback of protected content
  • Two integrated 400MHz 30-bit RAMDACs
    • Each supports analog displays connected by VGA at all resolutions up to 2048x1536
  • DisplayPort output support
    • Supports 24- and 30-bit displays at all resolutions up to 2560x1600
    • Integrated HD audio controller with up to 2 channel 48 kHz stereo or multi-channel (7.1) AC3 enabling a plug-and-play cable-less audio solution
  • HDMI output support
    • Supports all display resolutions up to 1920x1080
    • Integrated HD audio controller with up to 2 channel 48 kHz stereo or multi-channel (7.1) AC3 enabling a plug-and-play cable-less audio solution
  • Integrated AMD Xilleon HDTV encoder
    • Provides high quality analog TV output (component/S-video/composite)
    • Supports SDTV and HDTV resolutions
    • Underscan and overscan compensation
  • Seamless integration of pixel shaders with video in real time
  • VGA mode support on all display outputs
ATI PowerPlay Technology
  • Advanced power management technology for optimal performance and power savings
  • Performance-on-Demand
    • Constantly monitors GPU activity, dynamically adjusting clocks and voltage based on user scenario
    • Clock and memory speed throttling
    • Voltage switching
    • Dynamic clock gating
  • Central thermal management – on-chip sensor monitors GPU temperature and triggers thermal actions as required

As the above list of specifications and features show, the new Radeon HD 4670 has essentially the exact same features as the cards in the Radeon HD 4800 series.  The Radeon HD 4670 offers DX10.1 and Shader Model 4.1 support.  These GPUs are manufactured on TSMC's 55nm process node and the cards support ATI's CrossFireX multi-GPU technology.

Since we've covered essentially all of the shared features of the Radeon HD 4800 and 4600 series cards before, we won't be going into them in depth again here.  However, we would recommend taking a look at a few recent articles to brush up on the tech, if you're so inclined.

Reading the articles above will lay the groundwork for much of what we'll be showing you on the pages ahead.  Because the new Radeon HD 4670 shares the same core architecture as the cards in the Radeon HD 4800 series, with some elements pared down to reduce die size, they have basically the same feature set and capabilities but differentiate in terms of performance.

A Closer Look At The Card

As we have already mentioned, the new Radeon HD 4670 is powered by a GPU that shares the same base architecture at the Radeon HD 4800 series, that has been scaled down for the mainstream market segment.  To see just what has been changed, we've got a breakdown of the Radeon HD 4600 series' features listed side-by-side with the previous-generation Radeon HD 3600.

As you can see, the Radeon HD 4600 series has been improved in every meaningful way over the previous generation.  The transistor count increased from 378M to 514M, which resulted in a 20% increase in die size, but AMD was able to use those transistors very effectively and have increased the 4600 series' anti-aliasing, Z/Stencil, and Texturing capabilities four-fold.  The number of stream processors in the GPU has increased from 120 to 320 (down from 800 in the RV770), and memory bandwidth has been increased to about 32GB/s, a bump of approximately 25%.  Those of you with good memories will realize that this new mainstream card has the same number of stream processors as last year's RV670--which was used on the Radeon HD 3870 and 3850.




Although its specifications reveal a much more powerful product than ATI's previous generation mainstream graphics card, the new Radeon HD 4670 is still an unassuming, single-slot card, with a relatively short PCB.  The card you see pictured here is equipped with 512MB of 1GHz GDDR3 memory with a 750MHz GPU clock.  Please note, however, that ATI has also informed us that 1GB versions of the HD 4670 are also slated to arrive, that use standard DDR3 memory to keep costs in-line. 

The single-slot cooler used in the card consists of a slim-line copper heatsink with a dynamically throttled fan, that proved to be nice and quiet during testing.  ATI was able to equip the card with a relatively quiet and small cooler because the Radeon HD 4670 has a max board power of only 59W, which is within PEG (PCI Express Graphics) specifications.  Since the card doesn't require exorbitant amounts of power, a supplemental PCI Express power connector is not necessary.

The outputs on the Radeon HD 4670 resemble just about every other modern graphics card and include dual, dual-link DVI outputs and an S-Video / HD component output.  HDMI out with audio is also supported through the use of a dongle--just like the Radeon HD 3800 and 4800 series cards.

Our Test Systems and 3DMark06

HOW WE CONFIGURED THE TEST SYSTEMS: We tested all of the graphics cards used in this article on either an Asus nForce 790i SLI Ultra based Striker II Extreme motherboard (NVIDIA GPUs) or an X48 based Asus P5E3 Premium (ATI GPUs) powered by a Core 2 Extreme QX6850 quad-core processor and 2GB of low-latency Corsair RAM. The first thing we did when configuring these test systems was enter their respective BIOSes and set all values to their "optimized" or "high performance" default settings. Then we manually configured the memory timings and disabled any integrated peripherals that wouldn't be put to use. The hard drive was then formatted, and Windows Vista Ultimate was installed. When the installation was complete we fully updated the OS, and installed the latest DX10 redist and various hotfixes, along with the necessary drivers and applications.

HotHardware's Test Systems
Intel and NVIDIA Powered

Hardware Used:
Core 2 Extreme QX6850 (3GHz)

Asus Striker II Extreme
(nForce 790i SLI Ultra chipset)

Asus P5E3 Premium
(X48 Express)

Radeon HD 4670 x 2
Radeon HD 3650
Radeon HD 3850
GeForce 9500 GT
GeForce 8600 GTS
GeForce 9600 GT
GeForce 9600 GSO

2048MB Corsair DDR3-1333 C7
(2 X 1GB)

Integrated Audio
Integrated Network

Western Digital "Raptor" 74GB
(10,000RPM - SATA)

Relevant Software:

Windows Vista Ultimate SP1
DirectX June 2008 Redist

NVIDIA Forceware v177.92 / v177.39
ATI Catalyst v8.53

Benchmarks Used:
3DMark06 v1.0.2
3DMark Vantage v1.0.1
Unreal Tournament 3 v1.2*
Crysis v1.2*
Half Life 2: Episode 2*
Enemy Territory: Quake Wars*

* - Custom Benchmark

Futuremark 3DMark06
Synthetic DirectX Gaming


3DMark06 is a synthetic benchmark, designed to simulate DX9-class game titles. This version differs from the earlier 3Dmark05 in a number of ways, and includes not only Shader Model 2.0 tests, but Shader Model 3.0 and HDR tests as well. Some of the assets from 3DMark05 have been re-used, but the scenes are now rendered with much more geometric detail and the shader complexity is vastly increased. Max shader length in 3DMark05 was 96 instructions, while 3DMark06 ups that number to 512. 3DMark06 also employs much more lighting and there is extensive use of soft shadows. With 3DMark06, Futuremark has also updated how the final score is tabulated. In this latest version of the benchmark, SM 2.0 and HDR / SM3.0 tests are weighted and the CPU score is factored into the final tally as well.

Please pay special attention to our graphs, as we have included data recorded with a pair of Radeon HD 4670 cards running in CrossFire mode alongside all of the other single-GPU configurations.

According to 3DMark06, the new Radeon HD 4670 performed quite well, besting the Radeon HD 3650 and GeForce 9500 GT by considerable margins.  The lesser known GeForce 9600 GSO pulled ahead of the new Radeon, however, as did the Radeon HD 3850 and GeForce 9600 GT.  As an side, the Radeon HD 4670 CrossFire setup showed significant scaling and obviously outpaced the single-GPU configurations.


As we drill down into 3DMark06's individual tests, we see how the final score was achieved.  While it performed well in the Shader Model 2.0 test, the new Radeon HD 4670 was much stronger--relatively speaking--in the Shader Model 3.0 / HDR test, where it missed the mark set by the GeForce 9600 GSO by only 146 points.

3DMark Vantage

Futuremark 3DMark Vantage
Synthetic DirectX Gaming

3DMark Vantage

The latest version of Futuremark's synthetic 3D gaming benchmark, 3DMark Vantage, is specifically bound to Windows Vista-based systems because it uses some advanced visual technologies that are only available with DirectX 10, which y isn't available on previous versions of Windows.  3DMark Vantage isn't simply a port of 3DMark06 to DirectX 10 though.  With this latest version of the benchmark, Futuremark has incorporated two new graphics tests, two new CPU tests, several new feature tests, in addition to support for the latest PC hardware.  We tested the graphics cards here with 3DMark Vantage's Performance preset option, which uses a resolution of 1280x1024, with no anti-aliasing or anisotropic filtering.

The performance breakdown with 3DMark Vantage looks much like it does with 3DMark06.  The Radeon HD 4670 clearly outperforms the GeForce 9500 GT and Radeon HD 3650, but can't quite keep up with the Radeon HD 3850, GeForce 9600 GT, or GeForce 9600 GSO; at least not in this synthetic benchmark.

The individual GPU tests that partially comprise the 3DMark Vantage suite tell essentially the same story, with the Radeon HD 4750 besting and falling victim to the same graphics cards mentioned above.

Half Life 2: Episode 2

Half Life 2: Episode 2
DirectX Gaming Performance

Half Life 2:
Episode 2

Thanks to the dedication of hardcore PC gamers and a huge mod-community, the original Half-Life was one of the most successful first person shooters of all time. And courtesy of an updated game engine, gorgeous visuals, and intelligent weapon and level designs, Half Life 2 became just as popular.  Episode 2 - the most recent addition to the franchise - offers a number of visual enhancements including better looking transparent texture anti-aliasing. These tests were run at resolutions of 1,280 x 1,024 and 1,680 x 1,050 with 4X anti-aliasing and 16X anisotropic filtering enabled concurrently.  Color correction and HDR rendering were also enabled in the game engine as well.  We used a custom recorded timedemo to benchmark all cards for these tests.

The performance results gathered from our custom Half Life 2: Episode 2 benchmark contradicts what was reported by the synthetic 3DMark06 and 3DMark Vantage benchmarks from the previous pages.  Here, the new Radeon HD 4670 was able to pull ahead of the Radeon HD 3850 and GeForce 9600 GT, and fell victim to only the more expensive GeForce 9600 GT.

Unreal Tournament 3

Unreal Tournament 3
DirectX Gaming Performance

Unreal Tournament 3

If you're a long-time PC gamer, the Unreal Tournament franchise should need no introduction.  UT's fast paced action and over the top weapons have been popular for as long as Epic has been making the games.  For these tests, we used the latest addition to the franchise, Unreal Tournament 3.  The game doesn't have a built-in benchmarking tool, however, so we enlisted the help of FRAPS here.  These tests were run at resolutions of 1,280 x 1,024 and 1,680 x 1,050 with no anti-aliasing or anisotropic filtering enabled, but with the UT3's in game graphical options set to their maximum values, with color correction enabled.

The results from our custom Unreal Tournament 3 benchmark somewhat mirror what we saw with Half Life 2: Episode 2.  In this test, the Radeon HD 4670 was once again able to outpace even the Radeon HD 3850.  However, this time around, the 9600 GSO and HD 4670 were on equal footing, with a slight edge going to the GSO at both resolutions.

Enemy Territory: Quake Wars

Enemy Territory: Quake Wars
OpenGL Gaming Performance

Enemy Territory:
Quake Wars

Enemy Territory: Quake Wars is Based on a radically enhanced version of id's Doom 3 engine and viewed by many as Battlefield 2 meets the Strogg, and then some.  In fact, we'd venture to say that id took EA's team-based warfare genre up a notch or two.  ET: Quake Wars also marks the introduction of John Carmack's "Megatexture" technology that employs large environment and terrain textures that cover vast areas of maps without the need to repeat and tile many smaller textures.  The beauty of megatexture technology is that each unit only takes up a maximum of 8MB of frame buffer memory.  Add to that HDR-like bloom lighting and leading edge shadowing effects and Enemy Territory: Quake Wars looks great, plays well and works high end graphics cards vigorously.  The game was tested with all of its in-game options set to their maximum values with soft particles enabled in addition to 4X anti-aliasing and 16x anisotropic filtering.

We saw more of the same in our custom Enemy Territory: Quake Wars benchmark.  Once again, the new Radeon HD 4670 was able to outgun every other card we tested, save for the more expensive GeForce 9600 GT.

Crysis v1.2

Crysis v1.2
DirectX 10 Gaming Performance


If you're at all into enthusiast computing, the highly anticipated single player, FPS smash-hit Crysis, should require no introduction. Crytek's game engine produces some stunning visuals that are easily the most impressive real-time 3D renderings we've seen on the PC to date.  The engine employs some of the latest techniques in 3D rendering like Parallax Occlusion Mapping, Subsurface Scattering, Motion Blur and Depth-of-Field effects, as well as some of the most impressive use of Shader technology we've seen yet.  In short, for those of you that want to skip the technical jib-jab, Crysis is a beast of a game.  We ran the full game patched to v1.2 with all of its visual options set to 'High' to put a significant load on the graphics cards being tested  A custom demo recorded on the Island level was used throughout testing.

Things were pretty tight in our custom Crysis benchmark.  Here, less than a single frame per second separated the Radeon HD 4670, Radeon HD 3850, and GeForce 9600 GSO, with the 4670 falling right in between the two.  The GeForce 9600 GT was once again the fastest of the single-GPU configurations we tested, and scaling with two Radeon HD 4670 cards in CrossFire mode was quite good.

SD and HD Video Performance

We also did some quick testing of the new Radeon HD 4670's video processing engine, in terms of both image quality and CPU utilization with some standard and high-definition video playback tests.

Video Playback Performance: SD and HD
HQV (coming soon) and H.264

Normally, we would use the HQV benchmark in this section of our video card evaluations, but the Radeon HD 4670 had severe issues with HQV with the pre-release driver we used for testing and scores produced by the card were meaningless.  We have been in contact with AMD in regard to the issues and were told that they would be resolved in an upcoming driver release we expect to have in the next day or two.  Once we have them, we will update this portion of the article with HQV scores.

In the meantime, because we saw issues with HQV, we decided to test DVD playback on the Radeon HD 4670 using a handful of store-bought, movies.  Superman Returns, Eragon, and the Illusionist, save for some flickering during the FBI warning on the Superman Returns disc, all worked well on the Radeon HD 4670 with both PowerDVD 8 and WinDVD 8.  Some DViX and MPG files we have in-house for reference also played back normally.

Next we conducted a test using an H.264 encoded movie trailer clip for "Beowulf" which is available for download on Apple's QuickTime HD website.  The CPU utilization data gathered during these tests was taken from Windows Vista's built-in Performance Monitor. The graphs show the CPU utilization for a GeForce 9500 GT and a Radeon HD 4670 using PowerDVD 8 Ultra to playback the QuickTime clip.

GeForce 9500 GT

Radeon HD 4670

With a fast quad-core processor powering our test system and an unencrypted HD video clip being played back, both of the cards we tested had low CPU utilization in this test.  We should note that with hardware acceleration disabled, playing this video clip results in about 12% - 15% average CPU utilization, so there is a marked improvement with both PureVideo HD and UVD 2.  Also note that with encrypted content, like many off the shelf Blu-Ray discs for example, CPU utilization will be measurably higher that what you see here.  However, both platforms should have no trouble playing back HD digital video.

Power Consumption and Noise

We'd like to cover a few final data points before bringing this article to a close. Throughout all of our benchmarking and testing, we monitored how much power our test systems were consuming using a power meter. Our goal was to give you an idea as to how much power each configuration used while idling and under a heavy workload. Please keep in mind that we were testing total system power consumption at the outlet here, not just the power being drawn by the motherboards alone.

Total System Power Consumption
Tested at the Outlet

The Radeon HD 4670's power consumption fell somewhere in between the Radeon HD 3650 and Radeon HD 3850.  Despite offering somewhat better performance than the Radeon HD 3850 in most of our in-game tests, the 4670's peak power consumption was actually slightly lower than the 3850.

In terms of its acoustics, there isn't much to speak about in regard to the Radeon HD 4670.  While the fan on the card does spin-up to a high speed that is easily audible during the boot-up process, the fan quickly spins down to near inaudible levels and it didn't spin up significantly during testing.  We should also note that the Radeon HD 4670 is much cooler to the touch than Radeon HD 4800 series cards, which should bode well for its long term reliability.

Our Summary and Conclusion

Performance Summary: The ATI Radeon HD 4670 proved to be an excellent performer, especially considering its low-power operation and affordable price.  In our synthetic 3DMark06 and 3DMark Vantage benchmarks, the Radeon HD 4670 trailed cards like the Radeon HD 3850 and GeForce 9600 GT/GSO, but handily outperformed the ATI Radeon HD 3650 and GeForce 9500 GT.  However, in our actual in-game tests, which use anti-aliasing and anisotropic filtering, the Radeon HD 4670 was able to outpace the Radeon HD 3850 and GeForce 9600 GSO more often than not and finished close behind the more expensive GeForce 9600 GT.


With each new generation of mainstream graphics cards, AMD and NVIDIA seemingly change the game.  On some levels, we can't help but be impressed by the Radeon HD 4670.  For under $80, users can now purchase a low-power, relatively quiet, and cool running graphics card that outperforms ATI's previous-gen mid-range card, the Radeon HD 3850, which launched at almost $200 less than a year ago.  That is a serious amount of horsepower for a minimal investment, which makes the Radeon HD 4670 a great choice for many different types of users, including casual gamers, gamers on a budget, or HTPC aficionados that also do some gaming on their systems.

The Radeon HD 4670 faces some stiff competition at the moment, however.  The mainstream graphics card market is currently flooded with solid offerings that differ only slightly in terms of price.  For example, GeForce 9600 GSO cards like the EVGA model we used for testing, are available for about $80 on up, after mail in rebates.  GeForce 9600 GT cards can be had for about $95 on up--again after mail in rebates--and 9500 GTs go for roughly $60 and up.  Radeon HD 3650 cards can also be found in the $60 range, and Radeon HD 3850s fall in somewhere around $85 and higher, depending on thier clock speeds and memory compliment.  If we disregard the lower performing 3650 and 9500 GT for a moment, that makes four solid cards with prices that differ by only about $15 to $20.  Until the previous-gen cards go EOL and prices shake out a bit further, consumers looking for a mainstream graphics card need to be extra vigilant. Consumers should also consider the importance of NVIDIA's support for PhysX and CUDA.  While there may not be many games or applications that fully exploit PhysX and CUDA at the moment, that may change over the life of these mainstream products.

Ultimately though, the new Radeon HD 4670 is yet another strong product from AMD's resurgant graphics division.  If you're in the market for a new mainstream graphics card, do yourself a favor and look into one of these puppies.

  • Affordable Price
  • Good Performance
  • Cool and Quiet
  • Low Power
  • Good CrossFire Scaling
  • GeForce 9600 GT only a few dollars more
  • HQV wouldn't run properly

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